A first user equipment (UE) may be configured to communicate wirelessly with a second UE. Specifically, the first UE may transmit data to and receive data from the second UE through a wired or wireless communications network. The first and second UEs may use the network to communicate using a variety of different applications. For example, the first UE may be a mobile originating (MO) UE while the second UE may be a mobile terminating (MT) UE for a voice call. The voice call may be performed in a variety of different manners. For example, when the MO or MT UE is connected to a legacy network, the voice call may be performed using circuit switching. In another example, when the MO or MT UE is connected to an Internet Protocol (IP) data transmission network, the voice call may be performed using Voice over IP (VoIP). More specifically, when the network is a Long Term Evolution (LTE) network, the VoIP call may be a Voice over LTE (VoLTE) call.
When the VoLTE call is performed, the MO and MT UEs may perform a setup procedure. Initially, when the MO and MT UEs connect to the LTE network, each UE may be associated with one or more default bearers with an associated base station of the LTE network to which the UE is connected that provide a best effort service in the exchange of data with the LTE network. Furthermore, when a particular application is being utilized such as the VoLTE call, each UE may be assigned a dedicated bearer with the associated base station that provides a dedicated tunnel for data to be transmitted with regard to the VoLTE call (e.g., the voice data). The dedicated bearer may provide a variety of functionalities such as improving throughput or guaranteeing a bit rate for the data to be transmitted. However, if the base station (e.g., an evolved Node B (eNB) with an LTE network) does not have sufficient resources to provide the dedicated bearer, the VoLTE call fails even when the MT UE has accepted the invite.